Governor Deval Patrick said today that David Meier, a former Suffolk County homicide prosecutor now in private practice, will lead the central office set up to review thousands of criminal cases potentially tainted by the mishandling of drug evidence in a state lab.

Patrick said Meier, a partner at Todd & Weld in Boston, will oversee officials from a range of state and federal agencies as well as defense attorneys and prosecutors who will sift through the 34,000 criminal cases that may have been jeopardized in the scandal at the now-shuttered Department of Public Health lab in Jamaica Plain.

“The job of the office is to make sure no one falls through the cracks,” Patrick said in a press conference with Meier outside the governor’s office.

Meier said he would approach the daunting task not as a prosecutor, defense attorney, or judge but “as an advocate for fairness and due process on behalf of the criminal justice system.”

The process has the potential to result in the early release of an undetermined number of prisoners. In two early cases of fallout from the lab scandal, two men convicted in drug cases walked free from Norfolk Superior Court today.

Also today, the attorney general’s office today said it would conduct a “broader investigation” of the drug analysis unit of the lab. That review will focus on cases beyond those handled directly by the chemist now at the epicenter of the case and will involve the hiring of independent forensic experts to guide the inquiry.

A top aide to Coakley said in letter to the Massachusetts District Attorneys Association and the Committee for Public Counsel Services, the public defender agency, “Our review is focused on whether any failures at the laboratory impacted the reliability of the results on cases beyond those handled directly by the chemist.”

Governor Patrick did not answer directly at the news conference when asked if he was worried about prisoners reoffending after they are released early.

“The general public wants justice to be done in given cases,” he said. “That means the evidence has got to be solid. It’s got to stand up. And in cases where the evidence doesn’t stand up, our system is about dealing with that, and that’s what we’re trying to do now.”

Annie Dookhan, a chemist who worked at the lab for nine years, allegedly mishandled drug evidence used in criminal cases by altering the weight of drugs, not calibrating machines correctly, and manipulating samples to test as drugs when they were not.

Dookhan may have handled 60,000 drug samples, in 34,000 cases, and some or all of the evidence may be tainted, State Police have told prosecutors.

Superior Court Judge Paul Troy on Wednesday vacated the conviction of a drug dealer, David Danielli, ordering him to be released 2½ years early from prison, because of questions raised about the handling of evidence in his case.

Bill Greene/Globe Staff

Convicted drug dealer David Danielli was released after appearing Thursday in Norfolk Superior Court.

Danielli walked out of Norfolk Superior Court in Dedham this afternoon without speaking to reporters and climbed into a car driven by his daughter. His attorney, John T. Martin, told reporters that since the evidence against Danielli was tainted, Danielli should not be kept behind bars.

At about the same time Danielli was being released, Judge Kenneth Fishman released Mark Troisi from state prison, where he was serving a sentence of five years and a day for cocaine possession. Charges were filed against Troisi in 2010 after Dedham police searched his home and allegedly found more than 300 grams of cocaine, 25 pounds of marijuana, and nearly $8,000 in cash.

Meier was for 12 years chief of the homicide unit under Suffolk District Attorney Daniel F. Conley and Conley’s predecessor, Ralph C. Martin 2d. During his years in that position, Meier was instrumental in freeing two men who had been wrongfully convicted of murder – Donnell Johnson, who had been imprisoned for killing 9-year-old Jermaine Goffigan in 1994 and Marlon Passley, who was imprisoned for the 1995 murder of 18-year-old Tennyson Drakes.

Once the innocent were freed, Meier then prosecuted the men authorities concluded had actually committed the crimes.

In 2007, Meier was recognized by Massachusetts Lawyers Weekly as a “Lawyer of the Year. He was praised for “working behind the scenes to seek justice for victims and their families, as well as those who had been wrongfully convicted,’’ according to the administration.

Meier left public service after 20 years as a prosecutor in Suffolk and Middlesex counties and joined the Boston law firm Todd & Weld LLP as a defense lawyer.

He most recently appeared in Somerville District Court to represent the Rev. Paul A. LaCharite, 65, of Boston who faces charges of sexually assaulting one of his parishioners at the St. James Episcopal Church in Somerville where LaCharite was assigned from 1989 to 2005. LaCharite has pleaded not guilty to all charges.

According to the Patrick administration, Meier’s staff will collect information on potentially impacted criminal cases from the Department of Public Health, courthouses, and the state departments of correction, parole, probation and youth services, along with the US Bureau of Prisons and the US attorney’s office for Massachusetts.

Meier’s team will then draw up a master list of the individuals that will be provided to both the defense bar and prosecutors who can then head into the courts to address any cases that need to be changed.

Meier will be paid $12,500 a month, the same salary as a Cabinet secretary. It is not clear how long his job will take, but Patrick said he expects the state will need to hire paralegals and other support staff and will need to seek additional funding from the Legislature.